Raz BBOTTLE TO THE FACESinger Hospitalized After Nightclub Attack

8/16/2013 12:15 AM PDT

Raz-B -- the former B2K singer -- was hospitalized in China yesterday after someone smashed him in the mouth with a glass bottle ... turning his face into a bloody mess.

The 28-year-old R&B star was performing at a nightclub in Zhejiang (birthplace of Qian Xuesen -- the "Father of Chinese Rocketry" ... yay science!).

Raz's rep tells TMZ ... during the performance, he noticed a fistfight in the crowd and went to go break it up -- when someone swung a bottle right into his moneymaker, causing several cuts ... including a deep gash on his lip.

We're told the Chinese police immediately stepped in ... grabbing the attacker AND Raz -- and dragging them both to jail.

Cops quickly released Raz after determining he did nothing wrong. Raz's rep says cops made the bottle thrower fork over roughly $5,000 to pay for Raz's medical expenses.

After the drama at the police station, Raz was finally taken to a hospital, where he underwent a 1-hour surgical procedure to repair the "hole" in his lip. The wound also required 4 stitches.

Raz issued a statement to TMZ saying, "F**k this s**t hurts. I have a f**king hole in my lip. Thank god I made it to the hospital."

Raz -- who's been in living in China for the past 3 years -- says he doesn't plan on pursuing legal action. He also says he plans to move back to the U.S. before the end of the year to focus on a "big comeback."